PDA

View Full Version : Why a Grease Cup and not a Grease Fitting???



gary350
12-19-2010, 11:54 AM
Why does a Bridgeport Mill have a grease cup here???

My mill has grease fittings in several places but every Bridgeport I have ever seen always has a grease cup here, (see the photo). Grease cup is above the power feed lever this is a variable speed mill. I can not get any grease to stay in I screw the cup all the way down then screw the cup out it sucks the grease back out. I worry it needs to be greased.

I screw the cup all the way in then screw it out it is still full it always sicks the grease back out. No matter how many times I screw the cup in then screw it out it is still full. I can not push grease into the hole with my finger and the cup is always full.

The tool and die shop where I worked once had grease cups on all 6 Bridgeport mills. The last 2 places I worked had grease cups on all their mills too same location. The tool and die shop that I do business with has grease cups on all their Bridgeport mills too so this must be something that comes from the factory.

I wonder if I can put a grease fitting for a grease gun in place of the grease cup but maybe it is not suppose to get much grease?

http://i43.photobucket.com/albums/e358/gary350/GCup.jpg

mickeyf
12-19-2010, 01:01 PM
The functional difference that comes to mind is that a grease cup delivers with very little pressure. A grease fitting may be used with a highly pressurized grease gun. Whether that has anything whatsoever to do with a Bridgeport I have no idea.

bborr01
12-19-2010, 01:36 PM
Gary,

Mine just has a pipe plug there. It has an oil cup centered to the right of it, centered on the head.

I dont think B'ports use grease in the head.

Brian

lakeside53
12-19-2010, 02:16 PM
If that's a varispeed head, the port is just so you can squirt in a teaspoon of light grease now and then, normally directly from the Lubriplate plastic tube.

The cup is not "stock" - someone added it for convenience.

The Artful Bodger
12-19-2010, 02:33 PM
Grease cups have a certain convenience in that the operator can give the cup a little twist whenever the mood takes them, rather than reaching for the grease gun.

Grease cups are also used on things such as water pumps on old tractors, cars and trucks etc. I presume the logic was that the factory supplied grease gun would be filled with chassis grease which is not what you want in the water pump, just my theories.

Arcane
12-19-2010, 04:17 PM
I remember seeing grease cups on an old threshing machine back in the late 50s. I believe they were more in use before grease guns became common and grease was bought in bulk. It was a small matter to fill all the cups and then as greasing was needed, give a twist as you walked by.

Fasttrack
12-19-2010, 04:23 PM
FWIW ... most of those "grease" zerks on your BP are NOT grease zerks. They are Alemite's high pressure oil fittings. Don't grease your table. Please. ;) It needs way oil or non-detergent oil, not grease.

gnm109
12-19-2010, 04:50 PM
If that's a varispeed head, the port is just so you can squirt in a teaspoon of light grease now and then, normally directly from the Lubriplate plastic tube.

The cup is not "stock" - someone added it for convenience.


As usual my friend and colleague Mr. Lakeside has the answer. Yes, dear readers, there is a need in a varispeed BP (or clone) for some grease now and then. In particular, the downfeed bevels might need some. They are located at the left side of the worm cradle. There is also a worm gear on the upper end of the spindle from whence the worm cradle derived its name. Don't ask me how to grease that one without disassembling the head, however.

My manuals (BP and Webb) state that some white grease is used. Apparently, the fitting on the left side of the head is the one for the grease while the other two fittings (my Webb has two others) are used for "light oil" which drains down through to the spindle bearings.

Here's where th e grease goes..........The pictures were taken when I was replacing both downfeed bevel gears due to indiscretions committed by a previous owner.

http://i144.photobucket.com/albums/r188/gnm109/Machinery/WebbRepairPictures014.jpg

http://i144.photobucket.com/albums/r188/gnm109/Machinery/WebbRepairPictures015.jpg

gary350
12-19-2010, 06:10 PM
It appears to me all the variable speed head machines have a grease cup I have been looking at photos and videos online so far every machine has a grease cup on the left a few inches behind the brake handle and just above the power feel lever.

Look at this video you can see the grease cup about 1/3 of the way into the video click stop when the camera moves up.

http://www.youtube.com/watch?v=8GN-kLRBHIA

Here is another video shows the grease cup on the left same place as others.

http://www.youtube.com/watch?v=8GN-kLRBHIA&p=86756359D370FF70

I am seeing the grease cup on Series 1 machines only and a few of them have a pipe plug in the hole where the grease cup should be.

This machine on ebay has no grease cup but the 2nd machine in the rear has a grease cup. Double click to make the photo get larger.

http://cgi.ebay.com/Bridgeport-Series1-Manual-Vertical-Milling-Knee-Machine_W0QQitemZ370455839798QQcategoryZ92150QQcmd ZViewItemQQ_trksidZp3286.m7QQ_trkparmsZalgo%3DLVI% 26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid %3D5767663991822668975

Some machine have no grease cup, the hole is plugged with a pipe plug. What should I do replace the grease cup with an oil fill cup????

gnm109
12-19-2010, 06:25 PM
It appears to me all the variable speed head machines have a grease cup I have been looking at photos and videos online so far every machine has a grease cup on the left a few inches behind the brake handle and just above the power feel lever.

Look at this video you can see the grease cup about 1/3 of the way into the video click stop when the camera moves up.

http://www.youtube.com/watch?v=8GN-kLRBHIA

Here is another video shows the grease cup on the left same place as others.

http://www.youtube.com/watch?v=8GN-kLRBHIA&p=86756359D370FF70

I am seeing the grease cup on Series 1 machines only and a few of them have a pipe plug in the hole where the grease cup should be.

This machine on ebay has no grease cup but the 2nd machine in the rear has a grease cup. Double click to make the photo get larger.

http://cgi.ebay.com/Bridgeport-Series1-Manual-Vertical-Milling-Knee-Machine_W0QQitemZ370455839798QQcategoryZ92150QQcmd ZViewItemQQ_trksidZp3286.m7QQ_trkparmsZalgo%3DLVI% 26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid %3D5767663991822668975

Some machine have no grease cup, the hole is plugged with a pipe plug. What should I do replace the grease cup with an oil fill cup????


The oil fill cups have a tube that reaches in. As long as the tube doesn't interfere with the guttyworks inside, you will be OK.

In the alternative, why worry? If the pipe plug isn't left too tight, it could be removed each time you lube and you could squirt either light oil or light grease depending upon which hole you are concerned with.

lakeside53
12-19-2010, 10:26 PM
I have two Varispeed BPs. Both have the factory 5/16" plug. The lubrication plate says to remove it every 6 months and insert 1/2 teaspoon of lubriplate #107.

6 months in a production environment; home shop... well... I probably should do that every few years ;)

J. Randall
12-19-2010, 11:32 PM
Gary, if that were my mill, I would fill the cup and then occasionally when running I would give it a turn or two. My guess is it would wick in in use while running, where it won't go with you trying to force a cup in at a time with it setting static.
James

gary350
12-19-2010, 11:41 PM
Gary, if that were my mill, I would fill the cup and then occasionally when running I would give it a turn or two. My guess is it would wick in in use while running, where it won't go with you trying to force a cup in at a time with it setting static.
James


I have been trying to explain the cup is full already. I screw it in all the way thinking grease is going in. Then I screw it completely off the cup is still full of grease. When I screw it off it sucks grease back out. I try to get more grease in the cup the best I can mound it up higher than the cup. I try to force grease in the hole on the side of the mill with my finger but it won't go in. When I put the cup on the mound of grease squirts out the side before the threads connect. It is like taking 1 step forward then 1 step back over and over and over. I'm not accomplishing anything.

J Tiers
12-19-2010, 11:43 PM
Those grease cups actually work.... you give them a twist every so often, and the grease goes wherever it flows, and is "used up" by the motion of whatever parts are being greased.... Next time you twist it, a but more goes in, and it gets used up.

Eventually, there is no more movement available, at which time you refill the cup, and start again.

Yes, it WILL pull out grease, but only at first. When the grease has gone to do its job, it ain't coming back...... You don't open it until you run out of movement. Then you clear out any dirty grease pulled back, fill it with new, and screw it in until teh grease starts to flow where it's needed. Then back to the "twist at recommended intervals" routine.

I have engines with those cups, and the cups work fine.

There is another type with a spring feed.

I have no idea if a B-P is supposed to have one or not.

Deepest_Valley
12-20-2010, 12:43 AM
You fill a grease cup completely full and then screw it back on just a few threads at first. Then screw it down a quarter to half turn ever so often. When it's all the way down, it's empty and time to refill. On old stuff like engines, usually before starting up you give all the grease cups a half turn and then another ever half hour or so while running.

lakeside53
12-20-2010, 12:56 AM
I have been trying to explain the cup is full already. I screw it in all the way thinking grease is going in. Then I screw it completely off the cup is still full of grease. When I screw it off it sucks grease back out. I try to get more grease in the cup the best I can mound it up higher than the cup. I try to force grease in the hole on the side of the mill with my finger but it won't go in. When I put the cup on the mound of grease squirts out the side before the threads connect. It is like taking 1 step forward then 1 step back over and over and over. I'm not accomplishing anything.


For a 1/2 teaspoon every 6 months (or so..), if it's any trouble I'd toss it. The threaded bore just empties into a void - nothing fancy on the inside.

bborr01
12-20-2010, 01:50 AM
I just looked at my B'port series I cnc and it also has a plug where yours has the grease plug.

Does yours have the oil cup in the front?

Brian

lakeside53
12-20-2010, 02:09 AM
Both of mine have a small oil cup to the front and also on the right side.

J. Randall
12-20-2010, 03:59 AM
[QUOTE=gary350]I have been trying to explain the cup is full already. I screw it in all the way thinking grease is going in. Then I screw it completely off the cup is still full of grease. When I screw it off it sucks grease back out. I try to get more grease in the cup the best I can mound it up higher than the cup. I try to force grease in the hole on the side of the mill with my finger but it won't go in. When I put the cup on the mound of grease squirts out the side before the threads connect. It is like taking 1 step forward then 1 step back over and over and over. I'm not accomplishing anything.[/QUOTE

Gary, I understood you just fine, just don't think it is supposed to work that way, was just suggesting another angle to try if you had not already. If you want to do it your way fill the cup and screw it all the way in and leave it for awhile, after some hrs of use back it out and see if it pull a full cup back out, or it has used some of the grease. You also may have hardened grease in the channel that just won't let any new grease in.
James

J Tiers
12-20-2010, 09:48 AM
[QUOTE=gary350]I have been trying to explain the cup is full already. I screw it in all the way thinking grease is going in. Then I screw it completely off the cup is still full of grease. .............[/QUOTE

Gary, I understood you just fine, just don't think it is supposed to work that way, ................

Correct, it doesn't work that way...

It isn't a clumsy way of transferring grease, its a way of having a supply of grease there on the spot, no grease gun required. Grease is forced into the bearing a little now, a little more later, over time, as needed. It isn't for "shooting" a bunch of grease in all at once, which is far better done with a gun.

Perhaps B-Port decided that it was better to shoot a bunch in every so often rather than depending on folks giving the cup a twist every so many hours. At least that way it GETS some grease, instead of having folks wonder what that goofy thing is on the side there.

vpt
12-20-2010, 09:53 AM
On the countershaft of my atlas lathe I drilled and installed grease zerks in the original grease caps. Works perfectly.

gary350
12-20-2010, 10:13 AM
I have had the grease cup full of grease and screwed all the way down for about 10 years. I remember filling it with grease and screwing it down 10 years ago. About a month ago I reasized I have not put grease in the cup for 10 years so I decided to fill it with grease but it is still full. Grease is not being used up. 10 years ago it seemed that grease was not going in then either.

Maybe it is not a problem. I just don't want something to ware out because it did not get lube. I bought this machine used 30 years ago I want to keep it in good condition. I don't know what this grease cup lubes?